1. Field of the Invention
The present invention relates to portable drug delivery systems. Specifically, the present invention relates to a belt-mounted hypodermic syringe discharge unit with a corresponding belt-mounted holster.
2. Prior Art
Medical personnel are sometimes required to administer subcutaneous injections to patients in the field or outside the confines of a medically sterile and temperature controlled clinical environment. Veterinarians are often called upon to administer injections to domestic livestock in barnyards, corrals, out-buildings, or on the open range. In a domestic livestock operation for example, ranchers or veterinarians are responsible for administering drug formulations to a large herd of livestock on a periodic basis. Such periods between injections may be as short as a few days. In these situations it is imperative that a drug delivery system provide a means for inoculating a large number of animals in a short amount of time. In order to effectively operate in these environments, a drug delivery system must be portable, reliable, convenient, and facilitate the quick administration of drug dosages to as many recipients as possible in minimal time.
In addition to ready portability and ease of use, such systems must be designed to minimize the risk of cross contamination between humans or animals. The typical prior art system uses disposable prefilled drug cartridges with attached cannulas (needles). These disposable cartridges can be prefilled with a variety of liquid formulations including antibiotics, steroids, vitamins, or formulations for increasing milk or meat yield in domestic animals. One particularly significant formulation is bovine somatotropin (BST) for use as an agent for increasing milk production efficiency of dairy cows. While the use of disposable cartridges significantly reduces the problem of cross contamination, several problems exist in the prior art. First, there is a tendency toward excess breakage of cannulas from the cartridges. Excess splitting of the cartridges is also present. These problems arise due to the viscous character of the formulations pre-filled in the cartridges. In order to overcome the formulation viscosity, a great deal of pressure must be applied to the syringe plunger in order to administer the formulation. The fact that some formulations must be refrigerated between the point of manufacture and the point of use exacerbates this problem.
In addition to the fact that some prior art systems using disposable cartridges experience breakage of the cartridge, another problem exists in the disposal of spent (used) cartridges. The sharp cannula attached to each disposable cartridge poses a health and safety hazard not only to animals and humans during the drug administration process, but also a hazard to the general public once the spent cartridges enter the stream of public waste disposal. In addition, some state and federal regulations require that spent drug cartridges be destroyed in order to prevent re-use of the cartridge. It is also advantageous to separate the metallic cannula from the typically plastic disposable cartridge in order that the two components of different characteristics may be disposed of separately. Prior art drug delivery systems typically do not provide a means for conveniently and safely removing the cannula from the spent disposable cartridge. Further, prior art systems typically do not provide a means for disposing of the cannula separate from the spent cartridge.
Prior art drug delivery systems experiencing breakage of disposable cartridges, or not providing ready means for destroying and disposing spent cartridges, cannot satisfy the requirements for an efficient and effective drug delivery system. Thus, an improved drug delivery system is needed.